The present invention relates to an ink-jet printing device having a ink-jet head purging arrangement.
Control of ink drops in an ink-jet printing device is essential in order to produce high quality printed documents. In order to always eject ink drops of a consistent amount at the proper speed and in the proper direction, it is necessary to create an appropriate environment for ink within the nozzles and ink chambers. Air bubbles entering the manifold or pressure chambers from the nozzles or ink tanks, air bubbles generated in the air chambers, and solid matter created from drying and the like are the main factors that prevent desirable quality in printing.
Conventionally, air bubbles and solid matter that are generated or that enter the printing head and ink supply device of an ink-jet printing device have been removed by a purging method which applies a desired pressure to the ink tank supplying the ink to forcefully expel the air bubbles and solid matter through the nozzles.
However, since a large amount of ink is expelled from the nozzles during purging, not only can the recording paper and surrounding area of the nozzles become stained with ink, but the expelled ink cannot be reused, making the process uneconomical.